CacheFiles: Fix memory leak in cachefiles_check_auxdata error paths (607566ae) · Commits · 戴 / test

In cachefiles_check_auxdata(), we allocate auxbuf but fail to free it if we determine there's an error or that the data is stale. Further, assigning the output of vfs_getxattr() to auxbuf->len gives problems with checking for errors as auxbuf->len is a u16. We don't actually need to set auxbuf->len, so keep the length in a variable for now. We shouldn't need to check the upper limit of the buffer as an overflow there should be indicated by -ERANGE. While we're at it, fscache_check_aux() returns an enum value, not an int, so assign it to an appropriately typed variable rather than to ret. Signed-off-by:

Josh Boyer <jwboyer@fedoraproject.org> Signed-off-by:

David Howells <dhowells@redhat.com> cc: Hongyi Jia <jiayisuse@gmail.com> cc: Milosz Tanski <milosz@adfin.com> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/cachefiles/xattr.c

+15 −14

Original line number	Diff line number	Diff line
		@@ -162,8 +162,9 @@ int cachefiles_update_object_xattr(struct cachefiles_object *object,
		int cachefiles_check_auxdata(struct cachefiles_object *object)
		{
		struct cachefiles_xattr *auxbuf;
		enum fscache_checkaux validity;
		struct dentry *dentry = object->dentry;
		unsigned int dlen;
		ssize_t xlen;
		int ret;

		ASSERT(dentry);
		@@ -174,22 +175,22 @@ int cachefiles_check_auxdata(struct cachefiles_object *object)
		if (!auxbuf)
		return -ENOMEM;

		auxbuf->len = vfs_getxattr(dentry, cachefiles_xattr_cache,
		xlen = vfs_getxattr(dentry, cachefiles_xattr_cache,
		&auxbuf->type, 512 + 1);
		if (auxbuf->len < 1)
		return -ESTALE;

		if (auxbuf->type != object->fscache.cookie->def->type)
		return -ESTALE;
		ret = -ESTALE;
		if (xlen < 1 \|\|
		auxbuf->type != object->fscache.cookie->def->type)
		goto error;

		dlen = auxbuf->len - 1;
		ret = fscache_check_aux(&object->fscache, &auxbuf->data, dlen);
		xlen--;
		validity = fscache_check_aux(&object->fscache, &auxbuf->data, xlen);
		if (validity != FSCACHE_CHECKAUX_OKAY)
		goto error;

		ret = 0;
		error:
		kfree(auxbuf);
		if (ret != FSCACHE_CHECKAUX_OKAY)
		return -ESTALE;

		return 0;
		return ret;
		}

		/*

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